Underground coal mine dual-mode drilling method and modified drill rod

Abstract

The invention relates to a coal mine underground dual-mode drilling method and a modified drill rod. The value range of the thickness of the root of a drill rod male head thread of a drill rod body is 11-19 mm. According to the scheme, drilling is achieved through dual-drive mode switching, drilling is conducted in a directional mode after rotary drilling is conducted by a certain depth, a deviated drilling track can be corrected to an original design track, blank zones are not prone to being generated in a coal seam, gas extraction is facilitated, and the safety of later coal mining is improved. Or the modified drill rod can be directionally driven by a hole bottom motor to drill, and rotary drilling is adopted when a complex coal seam is encountered, so that the drilling efficiency in the complex coal seam is improved, and the risk of fracture of the modified drill rod in the complex coal seam is reduced. And due to switching of the dual-mode driving mode, deviation can be corrected after the device penetrates through a complex coal seam, and blank zones are reduced. The root part of the male head thread of the drill rod body of the modified drill rod is kept to be thicker, so that the rotary drilling requirement is met, and the drill rod is not easy to break.

Description

Technical Field

[0001] This invention relates to the technical field of shallow hole drilling in coal mines, and more particularly to a dual-mode drilling method for underground coal mines and a modified drill pipe. Background Technology

[0002] In coal mine drilling operations, shallow holes around 200 meters deep are drilled using rotary drilling with ordinary drill rods, while deep holes over 1,000 meters deep are drilled using directional drill rods in conjunction with a hydraulically driven bottom-hole motor. In other words, ordinary drill rods and directional drill rods have their own specific applications, and each type is suitable for different drilling depths.

[0003] When using conventional drill pipes, the drilling path may deviate due to the complex geological conditions within the coal seam. Furthermore, because they lack signal transmission capabilities, the actual drilling path can only be measured after the conventional drill pipe is withdrawn from the borehole and re-inserted using a position sensor, making timely correction of the drilling path impossible. Directional drill pipes, on the other hand, frequently experience "blowout" during rotary drilling, making them unsuitable for widespread use in shallow-hole operations where high rotary drilling requirements are necessary.

[0004] Therefore, it is necessary to provide a new shallow hole drilling scheme to achieve more efficient shallow hole drilling operations. Summary of the Invention

[0005] Therefore, it is necessary to provide a dual-mode drilling method and a modified drill pipe for underground coal mines to solve the problem of low efficiency in shallow hole drilling operations.

[0006] To achieve the above objectives, the inventors provide a dual-mode drilling method for underground coal mines, comprising the following steps:

[0007] Step 1: The modified drill rod carries a bottom hole motor but does not require hydraulic drive. The drilling rig drives the modified drill rod to rotate and drill into the coal seam.

[0008] Step 2: After all the modified drill pipes have been drilled, stop the drilling rig and measure the drilling path;

[0009] Step 3: After drilling to a certain depth, switch the drilling rig drive rotation to hydraulic drive. The bottom hole motor is driven by hydraulic drive to drag the bottom hole motor into the coal seam for directional drilling and to correct path deviations.

[0010] Step 4: After correcting the path, switch back to the drill rod rotation drive and repeat steps 1 to 3 until the preset hole depth is reached; or drill directionally to the preset hole depth using the hydraulic drive method in step 3.

[0011] The modified drill pipe includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

[0012] The inventors also provide a dual-mode drilling method for underground coal mines, comprising the following steps:

[0013] Step 1: The bottom-hole motor, driven by hydraulic pressure, drags the modified drill rod into the coal seam for drilling.

[0014] Step 2: After each modified drill pipe has been drilled, stop the hydraulic drive and measure the drilling path;

[0015] Step 3: When encountering a complex coal seam that causes the bottom hole motor to jam, stop the hydraulic drive and switch to the drilling rig to drive the modified drill rod to rotate and continue drilling into the coal seam, and measure the deviation path of this drilling process;

[0016] Step four: After passing through the complex coal seam, switch back to hydraulic drive. The bottom hole motor will then drive the modified drill rod under hydraulic drive to continue directional drilling into the coal seam and correct the path deviation in step three.

[0017] The modified drill pipe includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

[0018] Furthermore, the diameter of the fluid channel in the modified drill pipe ranges from 18 to 23 mm.

[0019] Furthermore, the male end of the drill pipe body is provided with a male countersunk hole, and the female end of the drill pipe body is provided with a female countersunk hole. The male countersunk hole and the female countersunk hole are used to engage and connect the communication component. The depth of the male countersunk hole corresponds to 2-3 turns of the effective engagement length of the external thread of the male end of the drill pipe.

[0020] The inventors also provide a modified drill pipe, comprising:

[0021] The drill pipe body has a male drill pipe end and a female drill pipe end at each end;

[0022] A communication component, inserted within the drill pipe body, includes an insulating tube, a conductive post, a first insulating positioning element, a second insulating positioning element, a first conductive connector, and a second conductive connector. The insulating tube is fitted inside the drill pipe body, and the conductive post is fitted inside the insulating tube. The first conductive connector passes through the first insulating positioning element and is screwed onto one end of the conductive post. The second conductive connector passes through the second insulating positioning element and is screwed onto the other end of the conductive post, such that the first and second insulating positioning elements are respectively engaged in the male countersunk hole and the female countersunk hole. One of the first and second insulating positioning elements has a limiting part on its outer wall to restrict its rotation relative to the drill pipe body. The first and second insulating positioning elements support the outer wall of the insulating tube to form a fluid channel with the inner wall of the drill pipe body.

[0023] The thickness of the root of the male thread of the drill pipe body is in the range of 11-19 mm.

[0024] Furthermore, the outer wall of the first insulating positioning member is provided with a limiting part, and the second insulating positioning member and / or the second conductive connector are provided with a screwing structure;

[0025] Alternatively, the outer wall of the second insulating positioning member may be provided with a limiting part, and the first insulating positioning member and / or the first conductive connector may be provided with a screwing structure.

[0026] Furthermore, the first conductive connector is a conductive female connector, and the second conductive connector is a conductive male connector.

[0027] Furthermore, the end faces of the first insulating positioning member and the first conductive connector facing the outside of the drill rod body are flush with the end face of the male drill rod head, and the second insulating positioning member and the second conductive connector are recessed into the female drill rod head.

[0028] Furthermore, when the outer wall of the first insulating positioning member is provided with a limiting part, the inner wall of the male drill pipe is provided with a limiting groove adapted to the limiting part; when the outer wall of the second insulating positioning member is provided with a limiting part, the inner wall of the female drill pipe is provided with a limiting groove adapted to the limiting part.

[0029] Furthermore, the first insulating positioning member includes an inner insulating positioning member ring, an outer insulating positioning member ring, and a connecting piece, wherein the inner insulating positioning member ring and the outer insulating positioning member ring are connected at intervals by the connecting piece; the second insulating positioning member has the same structure as the first insulating positioning member.

[0030] Unlike existing technologies, the above technical solution has the following advantages: This solution achieves drilling through dual-drive mode switching. After rotary drilling to a certain depth, it switches to directional drilling, which can correct any deviations in the borehole trajectory back to the original design trajectory, reducing the likelihood of blank zones in the coal seam, facilitating gas extraction, and improving the safety of subsequent coal mining. Alternatively, a modified drill rod can be used for directional drilling driven by a bottom-hole motor, switching to rotary drilling when encountering complex coal seams, improving drilling efficiency in complex coal seams and reducing the risk of modified drill rod breakage in complex coal seams. The dual-drive mode switching can also correct deviations even after passing through complex coal seams, reducing the generation of blank zones. The modified drill rod body and the root of the male thread on the drill rod maintain a large thickness, meeting the requirements of rotary drilling without easily breaking.

[0031] A fluid channel is formed by supporting a first insulating positioning element and a second insulating positioning element. These elements, along with the insulating tube, isolate the fluid channel from the conductive pillar, the first conductive connector, and the second conductive connector, preventing contact between the conductive parts within the communication component and the liquid in the fluid channel. A limiting part is provided on the outer wall of either the first or second insulating positioning element to prevent relative rotation between the communication component and the drill rod body during use. This application achieves the communication function of a common drill rod through a simple structure and can be directly modified from existing common drill rods, resulting in a high degree of modification feasibility. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of rotary drilling driven by a drilling rig in the underground supplementary drilling method of coal mines in this embodiment;

[0033] Figure 2 This is a schematic diagram of the bottom hole motor driving drilling in the underground supplementary drilling method of coal mines in this embodiment;

[0034] Figure 3 This is an internal sectional view of the male drill pipe end of the modified drill pipe in this embodiment;

[0035] Figure 4 This is an internal sectional view of the drill pipe head of the modified drill pipe in this embodiment;

[0036] Figure 5 This is a perspective view of the modified drill pipe in this embodiment;

[0037] Figure 6 This is another perspective view of the modified drill pipe in this embodiment;

[0038] Figure 7 This is a top view showing the arrangement of the first insulating positioning element and the first conductive connector in this embodiment;

[0039] Figure 8This is a perspective view showing the arrangement of the first insulating positioning element and the first conductive connector in this embodiment;

[0040] Figure 9 This is a perspective view showing the arrangement of the second insulating positioning element and the second conductive connector in this embodiment;

[0041] Figure 10 This is a schematic diagram of the connection between the male and female drill pipe ends in this embodiment.

[0042] Explanation of reference numerals in the attached figures:

[0043] 01. Modified drill pipe;

[0044] 11. Drill pipe body;

[0045] 12. Male drill pipe end;

[0046] 13. Drill pipe head;

[0047] 14. Sealing ring;

[0048] 21. Insulating tube;

[0049] 22. Conductive column;

[0050] 23. First insulating positioning component;

[0051] 24. Second insulating positioning component;

[0052] 231. Inner ring of insulating positioning component;

[0053] 232. Insulating positioning component outer ring;

[0054] 233. Connecting piece;

[0055] 25. First conductive connector;

[0056] 26. Second conductive connector;

[0057] 271. Limiting part;

[0058] 272. Limiting groove;

[0059] 28. First insulating washer;

[0060] 29. Second insulating washer;

[0061] 3. Fluid channels;

[0062] 41. Drill bit;

[0063] 42. No magnetic drill rod at the bottom;

[0064] 43. Probe;

[0065] 44. No magnetic drill rod at the top;

[0066] 45. Drilling rig;

[0067] 46. ​​Water tank;

[0068] 47. Pressure pump;

[0069] 48. Water tail;

[0070] 49. Bottom-of-hole motor;

[0071] 5. Coal seam;

[0072] 52. Drilling. Detailed Implementation

[0073] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0074] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0075] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0076] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0077] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0078] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0079] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0080] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0081] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0082] In coal mine mining scenarios with a depth of 200 meters, conventional drill pipes are used for drilling. The power source for conventional drill pipes is their mechanical rotation. The drill bit is connected to the front end of the drill pipe, and the rotation of the drill pipe drives the drill bit to drill into the coal seam—the most traditional drilling drive method. Conventional drill pipes are characterized by "low cost, fast construction, simple operation, and high adaptability," precisely matching the core needs of shallow-hole operations in coal mines. The specific drilling method involves drilling multiple holes on the coal face until effective extraction reaches the required standard. Conventional drill pipes primarily use vertical drilling, but due to the complex geological conditions in the coal seam and the uncontrollable drilling trajectory, the preset drilling path of conventional drill pipes may deviate during drilling due to complex geological conditions, creating blank zones in the coal seam. These blank zones cannot be extracted to the standard value of gas, posing a safety hazard for later coal mining operations.

[0083] Directional drill pipes are primarily used for long-distance (typically over a kilometer) drilling operations with complex trajectories. They enable precise three-dimensional spatial trajectory control. Shallow holes of 200 meters are typically straight-line drills, requiring no complex trajectory control; therefore, directional drill pipes are not chosen for 200-meter coal mining projects. The power source for directional drill pipes is hydraulic drive. Specifically, a hydraulically driven bottom-hole motor drags the directional drill pipe into the coal seam. During this process, the drill pipe itself does not rotate, resulting in significantly lower drilling efficiency compared to the rotary drilling method of ordinary drill pipes. In case of occasional situations such as jamming, the drilling rig 45 will drive the directional drill pipe to rotate. However, due to the thin threaded wall of the directional drill pipe, the threaded wall is highly susceptible to breakage when the drilling rig 45 drives rotary drilling or rotation. The conventional working mode of directional drill rods is to use a hydraulically driven bottom hole motor to drag the non-rotating directional drill rod through the coal seam. In occasional cases, the directional drill rod itself may rotate during drilling or retrieval. During the rotation and retrieval of the directional drill rod, it is very easy for it to break due to its thin threaded wall. Drilling must be stopped immediately and a retrieval tool must be used to retrieve the broken directional drill rod left in the borehole, which prolongs the construction cycle.

[0084] This application aims to provide a method that allows two drilling modes to be completed without retracting the drill bit in the same drilling path. That is, in the same drilling path, one can choose to use a hydraulically driven bottom hole motor to drag the modified drill rod for drilling, or one can choose to use a 45° rotating drill rig for drilling.

[0085] like Figures 1 to 2 This application provides a dual-mode drilling method for underground coal mines, including the following steps: Step 1, the modified drill rod 01 carries the bottom hole motor 49 without hydraulically driving the bottom hole motor 49, and the drilling rig 45 drives the modified drill rod 01 to rotate and drill into the coal seam 5.

[0086] Step 2: After drilling of each modified drill rod 01 is completed, stop the drilling machine 45 and measure the drilling path;

[0087] Step 3: After drilling to a certain depth, the rotation drive of the drilling rig 45 is changed to hydraulic drive. Under the hydraulic drive, the bottom hole motor 49 is dragged into the coal seam 5 for directional drilling and the path deviation is corrected.

[0088] Step 4: After correcting the path, switch back to the drill rod rotation drive and repeat steps 1 to 3 until the preset hole depth is reached; or drill directionally to the preset hole depth using the hydraulic drive method in step 3.

[0089] The modified drill pipe 01 includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

[0090] The modified drill rod 01 used in this embodiment is a modified ordinary drill rod used in 200-meter shallow hole scenarios. A male countersunk hole is machined at the male end of the ordinary drill rod, and a female countersunk hole is machined at the neck of the female end. A communication component is installed inside the ordinary drill rod, with its first and second insulating positioning components respectively engaging within the male and female countersunk holes, thus fixing the communication component inside the ordinary drill rod to form the modified drill rod 01 of this application. The modified drill rod 01 has communication functionality. A non-magnetic drill rod 44, a probe 43, and a lower non-magnetic drill rod 42 are installed at the front end of the modified drill rod 01. After each modified drill rod 01 drills, the position information of the borehole 52 front end can be measured from the communication component interface at the rear end of the drill rod. The position information of the borehole front end is measured after each modified drill rod 01 drills, and the drilling path can be obtained based on this position information.

[0091] Before drilling, a non-magnetic drill rod 44, a probe 43, a lower non-magnetic drill rod 42, a bottom-hole motor 49, and a drill bit 41 are installed on the front end of the modified drill rod 01. The drill rod is then mounted on the drilling rig 45. The drilling rig 45 is started, rotating and pushing the drill rod into the coal seam 5 to form a borehole. The bottom-hole motor 49 is then installed on the front end of the modified drill rod 01, but the drilling rig 45 still drives the modified drill rod 01 to rotate and drill into the coal seam 5, carrying the bottom-hole motor 49. After each modified drill rod 01 has drilled, the drilling rig 45 is stopped. The position information of the borehole front end can be measured from the communication component interface at the rear end of the drill rod. A new modified drill rod 01 is then connected, and the above steps are repeated. The position information of the borehole front end is measured after each modified drill rod 01 has drilled, and the drilling path can be obtained based on this position information. Due to the complex geological conditions of coal seam 5, the planned drilling route may deviate during drilling by the drill bit 41 due to impurities such as rocks in coal seam 5. After drilling to a certain depth, the modified drill rod 01 is kept in position, and the rotary drive of the drilling rig 45 is stopped and replaced with hydraulic drive. The bottom hole motor 49 works in conjunction with the drilling rig 45, and the path measured by the communication component inside the modified drill rod 01 can be adjusted in real time to correct path deviations and achieve directional drilling. When the drilling path returns to the designed path, the hydraulic drive can be stopped and the drilling rig 45 can be switched back to drive the drill rod to rotate and drill, repeating the process of "drill rod rotation drilling - bottom hole motor 49 hydraulic drive dragging modified drill rod 01 drilling - drill rod rotation drilling - bottom hole motor 49 hydraulic drive dragging modified drill rod 01 drilling..." until the preset hole depth is reached. Of course, after switching to directional drilling, it is also possible to continue directional drilling until the preset hole depth is reached.

[0092] This scheme primarily uses rotary drilling, supplemented by directional drilling for correction. Compared to conventional drill pipe drilling, the modified drill pipe 01 continues to use rotary drilling, utilizing an internally added communication component to measure the drilling position and draw the drilling path during the interval between each modified drill pipe 01 connection. This eliminates the need to remove the drill pipe after completing the predetermined hole depth and re-insert the position sensor to measure the drilling path, simplifying the construction process and improving efficiency. After drilling to a certain depth, switching to directional drilling corrects any deviations in the borehole trajectory back to the original design trajectory, reducing the likelihood of creating blank zones in coal seam 5, which is beneficial for gas extraction and improves the safety of subsequent coal mining. This scheme is particularly suitable for projects with relatively low trajectory requirements; the trajectory formed by the dual-mode hybrid drive drilling only needs to be approximately accurate. This scheme is especially suitable for scenarios where rotary drilling is used to escape from soft coal seam 5, and directional drilling is used to correct the trajectory.

[0093] like Figures 1 to 2 This application also provides a dual-mode drilling method for underground coal mines, including the following steps: Step 1, the bottom hole motor 49, under hydraulic drive, drags the modified drill rod 01 to drill into the coal seam 5;

[0094] Step 2: After drilling of each modified drill rod 01 is completed, stop the hydraulic drive and measure the drilling path;

[0095] Step 3: When encountering a complex coal seam 5 that causes the bottom hole motor 49 to jam, stop the hydraulic drive and switch to the drilling rig 45 to drive the modified drill rod 01 to rotate and continue drilling into the coal seam 5, and measure the deviation path of this drilling process.

[0096] Step 4: After passing through the complex coal seam 5, switch back to hydraulic drive. The bottom hole motor 49 will continue to directionally drill into the coal seam 5 under hydraulic drive, and correct the path deviation in step 3.

[0097] The modified drill pipe 01 includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

[0098] The modified drill rod 01 used in this embodiment is a modified ordinary drill rod used in 200-meter shallow hole scenarios. A male countersunk hole is machined at the male end of the ordinary drill rod, and a female countersunk hole is machined at the neck of the female end. A communication component is installed inside the ordinary drill rod, with its first and second insulating positioning components respectively engaging within the male and female countersunk holes, thus fixing the communication component inside the ordinary drill rod to form the modified drill rod 01 of this application. The modified drill rod 01 has communication functionality. A non-magnetic drill rod 44, a probe 43, and a lower non-magnetic drill rod 42 are installed at the front end of the modified drill rod 01. After each modified drill rod 01 drills, the position information of the borehole 52 front end can be measured from the communication component interface at the rear end of the drill rod. The position information of the borehole front end is measured after each modified drill rod 01 drills, and the drilling path can be obtained based on this position information. This solution is particularly suitable for projects with relatively high trajectory requirements. The dual-mode hybrid drive drilling forms a more accurate drilling trajectory and can smoothly and efficiently pass through complex coal seams.

[0099] Before drilling, a non-magnetic drill rod 44, a probe 43, a lower non-magnetic drill rod 42, a bottom hole motor 49, and a drill bit 41 are installed at the front end of the modified drill rod 01. The bottom hole motor 49 is hydraulically driven, and its rotation drags the modified drill rod 01 forward to form a borehole. During the process, the bottom hole motor 49 works in conjunction with the drilling rig 45. Using the path measured by the communication component inside the modified drill rod 01, its drilling direction can be adjusted in real time to correct path deviations and achieve directional drilling. After each modified drill rod 01 has drilled, the drilling rig 45 is stopped. The position information of the borehole front end can be measured from the communication component interface at the rear end of the drill rod. Then, a new modified drill rod 01 is connected, and the above steps are repeated. The position information of the borehole front end is measured after each modified drill rod 01 has drilled, and the drilling path can be obtained based on this position information. Due to the complex geological conditions of coal seam 5, during the drilling process of drill bit 41, the bottom-hole motor 49 may get stuck due to rocks and other impurities in coal seam 5. Maintaining the position of the modified drill rod 01, the hydraulic drive is stopped, and the drilling rig 45 drives the modified drill rod 01 to rotate and continue drilling into coal seam 5. The drilling rig 45 rotates and advances the drill rod into coal seam 5. Simultaneously, after each modified drill rod 01 has drilled, the position information of the borehole tip is measured. Based on this position information, the deviation path during the rotary drilling process driven by the drilling rig 45 can be obtained. After passing through the complex coal seam 5, the system switches back to hydraulic drive for directional drilling with the bottom-hole motor 49. If a new complex coal seam 5 is encountered during drilling, the system switches back to hydraulic drive and then to rotary drive by the drilling rig 45, repeating the switching between the two drive modes until the preset hole depth is reached.

[0100] This application primarily employs directional drilling, supplemented by rotary drilling. Compared to conventional drill pipe drilling methods, the modified drill pipe 01 can be driven directionally by the bottom-hole motor 49, switching to rotary drilling when encountering complex coal seams 5. This improves drilling efficiency in complex coal seams 5 and reduces the risk of modified drill pipe 01 breakage. The dual-mode drive switching also allows for correction after passing through complex coal seams 5, reducing the generation of blank zones. This solution utilizes an internally added communication component to measure the drilling position and draw the drilling path during the interval between each modified drill pipe 01 connection. It eliminates the need to remove the drill pipe after completing the predetermined hole depth and re-insert the position sensor to measure the drilling path, simplifying the construction process and improving efficiency. This solution is particularly suitable for scenarios involving directional drilling trajectory design and rotary drilling to escape from soft coal seams 5.

[0101] The aforementioned hydraulic drive requires a water supply device, which includes a water tank 46 and a booster pump 47. The water tank 46 is connected to the water tail 48 via the booster pump 47. The water in the water tank 46 is pressurized by the booster pump 47 and then flows through the water tail 48 to drive the rotor in the bottom hole motor 49 of the modified drill rod 01 to rotate, thereby driving the drill bit 41 to rotate.

[0102] The root of the male thread on the drill pipe body refers to the position on the male head of the drill pipe closest to the female head. The thickness value refers to the vertical distance between the crest of the thread and the inner wall of the drill pipe body.

[0103] During rotary drilling and rotation, the thread root of the drill pipe male end bears most of the torque during drill pipe rotation. Therefore, drill pipe fracture usually occurs at the thread root of the drill pipe male end, making the thickness of the thread root of the drill pipe male end crucial. The thread root thickness of the modified drill pipe 01 drill pipe body drill pipe male end ranges from 11-19mm, which is much greater than the thread root wall thickness of the male end of commercially available directional drill pipes.

[0104] In some embodiments, the fluid channel diameter of the modified drill pipe 01 ranges from 18 to 23 mm.

[0105] In some embodiments, the male end of the drill pipe body has a countersunk hole, and the female end of the drill pipe body has a countersunk hole. The countersunk holes are used to engage and connect the communication component. The depth of the countersunk hole corresponds to 2-3 turns of the effective engagement length of the male thread of the drill pipe. The countersunk hole extends inward from the end of the male end of the drill pipe body to 2-3 turns of the effective engagement length of the male thread of the drill pipe, preserving the thread wall thickness at the root of the male end of the drill pipe as far as possible to resist the torque during rotary drilling and rotation of the modified drill pipe 01, and to prevent breakage at the root of the male thread of the drill pipe.

[0106] Please see Figure 3-10 This embodiment provides a dual-mode drilling method for underground coal mines, comprising:

[0107] The drill pipe body 11 has a drill pipe male head 12 and a drill pipe female head 13 at its two ends respectively;

[0108] The communication component, which is installed within the drill pipe body 11, includes an insulating tube 21, a conductive post 22, a first insulating positioning element 23, a second insulating positioning element 24, a first conductive connector 25, and a second conductive connector 26. The insulating tube 21 is fitted inside the drill pipe body 11, the conductive post 22 is fitted inside the insulating tube 21, the first conductive connector 25 passes through the first insulating positioning element 23 and is screwed to one end of the conductive post 22, and the second conductive connector 26 passes through the second insulating positioning element 24. 4 is screwed into the other end of the conductive post 22, so that the first insulating positioning member 23 and the second insulating positioning member 24 are respectively locked into the drill rod male head 12 and the drill rod female head 13. One of the first insulating positioning member 23 and the second insulating positioning member 24 is provided with a limiting part 271 on its outer wall to restrict its rotation relative to the drill rod body 11. The first insulating positioning member 23 and the second insulating positioning member 24 support the outer wall of the insulating tube 21 and the inner wall of the drill rod body 11 to form a fluid channel 3.

[0109] When the male drill pipe head 12 of different modified drill pipes is adapted to and sealed with the female drill pipe head 13, the first conductive connector 25 and the second conductive connector 26 are adapted to and connected.

[0110] The cross-sections of the drill pipe male head 12, drill pipe female head 13, first conductive connector 25, and second conductive connector 26 are configured to be circular, so that when the drill pipe male head 12 and drill pipe female head 13 are screwed together, the first conductive connector 25 and the second conductive connector 26 can rotate relative to each other.

[0111] The male drill pipe end 12, the female drill pipe end 13, and the drill pipe body 11 are fixed together by welding.

[0112] The insulating tube 21, the first insulating positioning element 23, and the second insulating positioning element 24 are made of insulating material, specifically plastic. The first conductive connector 25 and the second conductive connector 26 of the conductive post 22 are made of metal material, specifically copper or other alloys. The position of the insulating tube 21 within the drill pipe body 11 is fixed by the first insulating positioning element 23 and the second insulating positioning element 24 to prevent the insulating tube 21 from wobbling in the axial and radial directions within the drill pipe body 11. The insulating tube 21, the first insulating positioning element 23, and the second insulating positioning element 24 isolate the fluid channel 3 from the conductive post 22, the first conductive connector 25, and the second conductive connector 26, preventing the liquid in the fluid channel 3 from contacting the conductive post 22 and causing a short circuit during drill pipe drilling.

[0113] The inner wall of the male drill pipe end 12 has a countersunk hole, and the inner wall of the female drill pipe end 13 also has a countersunk hole. The first insulating positioning member 23 is inserted into the male drill pipe end 12 from the outside. The first insulating positioning member 23 is axially locked by the countersunk hole and will not move further into the drill pipe body 11. When the first conductive connector 25 and the conductive post 22 are connected, the first insulating positioning member 23 will be further fixed, preventing the first insulating positioning member 23 from exiting from the end of the male drill pipe end 12 (i.e., the end of the male drill pipe end 13). 2) The end away from the drill pipe body 11 is disengaged; the second insulating positioning member 24 will be installed from outside the drill pipe female head 13 into the drill pipe female head 13. The second insulating positioning member 24 is locked in the axial direction by the countersunk hole of the female head and will not continue to move into the drill pipe body 11. When the second conductive connector 26 and the conductive post 22 are connected, the second insulating positioning member 24 will be further fixed to prevent the second insulating positioning member 24 from disengaging from the end of the drill pipe female head 13 (i.e. the end of the drill pipe female head 13 away from the drill pipe body 11).

[0114] To prevent the communication component from rotating within the drill pipe body 11 during drilling, a limiting part 271 is provided in one of the first insulating positioning member 23 and the second insulating positioning member 24. The limiting part 271 restricts the position of the communication component within the drill pipe body 11, preventing rotation. The end without the limiting part 271 can meet the requirements for threaded tightening.

[0115] The limiting part 271 can specifically be a semi-cylindrical structure protruding from its surface. The limiting part 271 extends a certain length from one end face of the first insulating positioning member 23, and the extension length of the limiting part 271 is less than the length of the first insulating positioning member 23. Alternatively, the limiting part 271 extends a certain length from one end face of the second insulating positioning member 24, and the extension length of the limiting part 271 is less than the length of the second insulating positioning member 24. In addition to a cylindrical structure with a semi-circular cross-section, it can also be a cylindrical structure with a triangular or square cross-section. Of course, in some embodiments, the limiting part 271 can also be a protrusion located in the middle of the outer wall of the insulating positioning member. That is, the limiting part 271 only needs to be able to restrict the relative rotation between the insulating positioning member and the drill rod body 11.

[0116] The mating connection between the male drill head 12 and the female drill head 13 of different modified drill pipes means that the end of the male drill head 12 of one modified drill pipe away from the drill pipe body 11 can be mated with the end of the female drill head 13 of another modified drill pipe away from the drill pipe body 11, thereby extending the length of the modified drill pipe and achieving the intended use. When the male drill head 12 and the female drill head 13 are typically threaded, after they are screwed into place, the end of the first conductive connector 25 away from the conductive post 22 is mated with the end of the second conductive connector 26 away from the conductive post 22, realizing the internal circuit connection of multiple modified drill pipes.

[0117] The male drill pipe end 12 and the female drill pipe end 13 are generally designed as a screw-in male and female structure, while the first conductive connector 25 and the second conductive connector 26 are usually designed as a plug-in male and female structure. During the screwing of the male drill pipe end 12 and the female drill pipe end 13, the first conductive connector 25 gradually adapts to the second conductive connector 26; conversely, when the male drill pipe end 12 and the female drill pipe end 13 are disassembled, the first conductive connector 25 also gradually separates from the second conductive connector 26.

[0118] In this application, the first insulating positioning member 23 and the second insulating positioning member 24 are used to support and form the fluid channel 3. These components, together with the insulating tube 21, isolate the fluid channel 3 from the conductive post 22, the first conductive connector 25, and the second conductive connector 26, preventing short circuits between the conductive parts of the communication component and the liquid in the fluid channel 3. Furthermore, a limiting part 271 is provided on the outer wall of the first insulating positioning member 23 or the second insulating positioning member 24 to prevent relative rotation between the communication component and the drill rod body 11 during drill rod use. This application achieves the communication function of the modified drill rod through a simple structure and can be directly modified from existing ordinary drill rods, resulting in a high degree of modification feasibility.

[0119] In some embodiments, the outer wall of the first insulating positioning member 23 is provided with a limiting portion 271, and the second insulating positioning member 24 and / or the second conductive connector 26 are provided with a screwing structure.

[0120] Alternatively, a limiting portion 271 may be provided on the outer wall of the second insulating positioning member 24, and a screwing structure may be provided on the first insulating positioning member 23 and / or the first conductive connector 25.

[0121] When the limiting part 271 is provided on the outer wall of the first insulating positioning member 23, the limiting part 271 will restrict the relative rotation of the first insulating positioning member 23 relative to the drill rod male head 12. In this case, in order to facilitate the screwing work inside the drill rod body 11, a screwing structure is provided on the second insulating positioning member 24 and / or the second conductive connector 26 at the other end, so as to screw the second conductive connector 26 onto the conductive post 22. The screwing structure provided on the second insulating positioning member 24 and / or the second conductive connector 26 means that the screwing structure is provided on the side of the second insulating positioning member 24 facing the outside of the drill rod female head 13, or the screwing structure is provided on the side of the second conductive connector 26 facing the outside of the drill rod female head 13, or both the second insulating positioning member 24 and the second conductive connector 26 are provided with screwing structures on the side facing the outside of the drill rod female head 13. Similarly, the outer wall of the second insulating positioning member 24 is provided with a limiting part 271, and the first insulating positioning member 23 and / or the first conductive connector 25 are provided with a screwing structure, which has a similar effect, and will not be described in detail here.

[0122] Taking the limiting part 271 on the outer wall of the first insulating positioning member 23 as an example, during installation, the conductive post 22 is inserted into the insulating tube 21, and the first conductive connector 25 is passed through the first insulating positioning member 23 and screwed onto one end of the conductive post 22. The pre-assembled component is then inserted into the drill rod body 11 from one end of the drill rod male end 12, with the first insulating positioning member 23 abutting against the male end countersunk hole. The second conductive connector 26 is passed through the second insulating positioning member 24 and screwed onto the other end of the conductive post 22, with the second insulating positioning member 24 also abutting against the female end countersunk hole in the drill rod body 11. After the second conductive connector 26 is screwed into place or the second insulating positioning member 24 abuts, the pre-assembled component is tightened and will not detach from the drill rod body 11. This structure is convenient and efficient to install.

[0123] like Figure 3-6 As shown, in some embodiments, the first conductive connector 25 is a conductive female connector, the second conductive connector 26 is a conductive male connector, the drill pipe male connector 12 is a conductive male connector, and the drill pipe female connector 13 is a conductive female connector. The alternating male and female design of the first conductive connector 25 and the drill pipe male connector 12 improves the structural compactness and facilitates obtaining a larger fluid channel 3. Similarly, the alternating male and female design of the second conductive connector 26 and the drill pipe female connector 13 improves the structural compactness and facilitates obtaining a larger fluid channel 3. A sealing ring 14 is embedded in the inner wall of the drill pipe female connector 13. When the drill pipe male connector 12 is inserted into the drill pipe female connector 13, the sealing ring 14 seals the two. Specifically, the sealing ring 14 is located at the end of the drill pipe female connector 13 facing the drill pipe body 11. The sealing ring 14 is positioned opposite the end of the second conductive connector 26.

[0124] like Figure 3 As shown, in some embodiments, the end faces of the first insulating positioning member 23 and the first conductive connector 25 facing outwards from the drill rod body 11 are flush with the end face of the drill rod male connector 12, and the second insulating positioning member 24 and the second conductive connector 26 are recessed into the drill rod female connector 13. The effect of aligning the end faces of the first insulating positioning member 23 and the first conductive connector 25 facing outwards from the drill rod body 11 with the end face of the drill rod male connector 12 away from the drill rod body is to prevent damage to the first or second insulating positioning member after the drill rod male and female connectors are threaded together. In embodiments where the second conductive connector is a conductive male connector, the second conductive connector needs to be recessed into the drill rod female connector to protect its structure and facilitate transportation and storage.

[0125] like Figure 7-8As shown, in some embodiments, the first conductive connector 25 and the first insulating positioning member 23 are an integral structure. The first conductive connector 25 and the first insulating positioning member 23 are inserts, with the metal first conductive connector 25 embedded in the plastic first insulating positioning member 23, which facilitates one-time installation and also avoids gaps between the two to prevent shaking.

[0126] like Figure 9 As shown, in some embodiments, the second conductive connector 26 and the second insulating positioning member 24 are an integral structure. The second conductive connector 26 and the second insulating positioning member 24 are inserts, with the metal second conductive connector 26 embedded in the plastic second insulating positioning member 24, which facilitates one-time installation and also avoids the gap between the two to prevent shaking.

[0127] like Figure 7-8 As shown, in some embodiments, when the outer wall of the first insulating positioning member 23 is provided with a limiting portion 271, the inner wall of the drill rod male head 12 is provided with a limiting groove 272 adapted to the limiting portion 271; when the outer wall of the second insulating positioning member 24 is provided with a limiting portion 271, the inner wall of the drill rod female head 13 is provided with a limiting groove 272 adapted to the limiting portion 271. Taking the outer wall of the first insulating positioning member 23 being provided with a limiting portion 271 as an example, the limiting groove 272 has a limiting function in two dimensions. After the limiting portion 271 is engaged in the limiting groove 272, the limiting groove 272 can prevent the first insulating positioning member 23 from rotating in the drill rod male head 12. The bottom of the limiting groove 272 (i.e., the side of the limiting groove 272 facing the drill rod body 11) is an abutment surface, which can limit the insertion depth of the limiting portion 271. Similarly, if the second insulating positioning member 24 is provided with a limiting portion, the limiting groove 272 in the drill rod female head 13 is also like this.

[0128] like Figure 5 As shown, in some embodiments, the limiting portions 271 are symmetrically arranged on the outer wall of the first insulating positioning member 23 or the outer wall of the second insulating positioning member 24; the number of limiting grooves 272 is the same as the number of limiting portions 271. The symmetrically arranged limiting portions 271 can better prevent rotation between the first insulating positioning member 23 and the male drill pipe end 12 (or between the second insulating positioning member 24 and the female drill pipe end 13).

[0129] like Figure 7-8 As shown, in some embodiments, the first insulating positioning member 23 includes an inner insulating positioning member 231, an outer insulating positioning member 232, and a connecting piece 233, wherein the inner insulating positioning member 231 and the outer insulating positioning member 232 are connected at intervals by the connecting piece 233; the second insulating positioning member 24 has the same structure as the first insulating positioning member 23.

[0130] The inner ring of the first insulating positioning member 23 has a ring-shaped columnar structure, and the first conductive connector 25 is fitted inside its inner ring. The outer wall of the outer ring is used to mate with the drill pipe male head 12. Similarly, the structure of the second insulating positioning member 24 is the same as that of the first insulating positioning member 23.

[0131] Taking the first insulating positioning member 23 as an example, the inner ring and outer ring of the positioning member have the same height, and the outer wall of the inner ring and the inner wall of the outer ring are equidistantly arranged. After the first insulating positioning member 23 and the second insulating positioning member 24 are installed, the distance between the inner ring and the outer ring determines the cross-sectional size of the fluid channel 3. Preferably, two connecting pieces 233 or connecting posts are symmetrically arranged between the inner ring and the outer ring of the positioning member, so that the inner ring and the outer ring of the positioning member form a stable connection relationship, while having a larger cross-section of the fluid channel 3. In the embodiment, the connecting piece 233 refers to a thin strip structure that is longitudinally arranged between the inner ring and the outer ring of the positioning member, which can occupy less fluid channel 3 size. In the embodiment, the connecting post refers to a columnar structure with a circular, square, elliptical or other shapes.

[0132] In this application, the fluid channel diameter refers to the inner diameter of the outer ring 232 of the insulating positioning element.

[0133] like Figure 5 , Figure 7-8 As shown, in this embodiment, when screwing the first insulating positioning member 23, the screwing tool can be directly placed on the connecting piece 233 for screwing, without the need for other screwing structures on the first insulating positioning member 23. Of course, in embodiments where the first insulating positioning member 23 and the first conductive connector 25 are integrally formed, the first conductive connector 25 also does not need to have an additional screwing structure.

[0134] like Figure 3-4 , Figure 10As shown, in some embodiments, a first insulating washer 28 is provided between the insulating tube 21 and the first insulating positioning member 23, and a second insulating washer 29 is provided between the insulating tube 21 and the second insulating positioning member 24. The first insulating washer 28 and the second insulating washer 29 can be made of silicone or rubber, achieving both insulation and sealing. After the first conductive connector 25 is passed through the first insulating positioning member 23 and screwed onto the conductive post 22, the first insulating positioning member 23 presses against the first insulating washer 28, sealing that position. Similarly, after the second conductive connector 26 is passed through the second insulating positioning member 24 and screwed onto the conductive post 22, the second insulating positioning member 24 presses against the second insulating washer 29, sealing that position. The first insulating washer 28 and the second insulating washer 29 also prevent liquid in the fluid channel 3 from flowing into the fluid channel 3 through the gap between the insulating tube 21 and the first insulating positioning member 23, or from flowing into the fluid channel 3 through the gap between the insulating tube 21 and the second insulating positioning member.

[0135] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A dual-mode drilling method for underground coal mines, characterized in that, Includes the following steps: Step 1: The modified drill rod carries a bottom hole motor but does not require hydraulic drive. The drilling rig drives the modified drill rod to rotate and drill into the coal seam. Step 2: After all the modified drill pipes have been drilled, stop the drilling rig and measure the drilling path; Step 3: After drilling to a certain depth, switch the drilling rig drive rotation to hydraulic drive. The bottom hole motor is driven by hydraulic drive to drag the bottom hole motor into the coal seam for directional drilling and to correct path deviations. Step 4: After correcting the path, switch back to the drill rod rotation drive and repeat steps 1 to 3 until the preset hole depth is reached; or drill directionally to the preset hole depth using the hydraulic drive method in step 3. The modified drill pipe includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

2. A dual-mode drilling method for underground coal mines, characterized in that, Includes the following steps: Step 1: The bottom-hole motor, driven by hydraulic pressure, drags the modified drill rod into the coal seam for drilling. Step 2: After each modified drill pipe has been drilled, stop the hydraulic drive and measure the drilling path; Step 3: When encountering a complex coal seam that causes the bottom hole motor to jam, stop the hydraulic drive and switch to the drilling rig to drive the modified drill rod to rotate and continue drilling into the coal seam, and measure the deviation path of this drilling process; Step four: After passing through the complex coal seam, switch back to hydraulic drive. The bottom hole motor will then drive the modified drill rod under hydraulic drive to continue directional drilling into the coal seam and correct the path deviation in step three. The modified drill pipe includes a communication component inserted inside the drill pipe body, and the thickness of the root of the male thread of the drill pipe body ranges from 11 to 19 mm.

3. The dual-mode drilling method for underground coal mines according to claim 1 or 2, characterized in that, The diameter of the fluid channel in the modified drill pipe ranges from 18 to 23 mm.

4. The dual-mode drilling method for underground coal mines according to claim 1 or 2, characterized in that, The male end of the drill pipe body is provided with a male countersunk hole, and the female end of the drill pipe body is provided with a female countersunk hole. The male countersunk hole and the female countersunk hole are used to engage and connect the communication component. The depth of the male countersunk hole corresponds to 2-3 turns of the effective engagement length of the external thread of the male end of the drill pipe.

5. A modified drill pipe, characterized in that, include: The drill pipe body has a male drill pipe head and a female drill pipe head at both ends. The male drill pipe head of the drill pipe body has a male countersunk hole, and the female drill pipe head of the drill pipe body has a female countersunk hole. A communication component, inserted within the drill pipe body, includes an insulating tube, a conductive post, a first insulating positioning element, a second insulating positioning element, a first conductive connector, and a second conductive connector. The insulating tube is fitted inside the drill pipe body, and the conductive post is fitted inside the insulating tube. The first conductive connector passes through the first insulating positioning element and is screwed onto one end of the conductive post. The second conductive connector passes through the second insulating positioning element and is screwed onto the other end of the conductive post, such that the first and second insulating positioning elements are respectively engaged in the male countersunk hole and the female countersunk hole. One of the first and second insulating positioning elements has a limiting part on its outer wall to restrict its rotation relative to the drill pipe body. The first and second insulating positioning elements support the outer wall of the insulating tube to form a fluid channel with the inner wall of the drill pipe body. The thickness of the root of the male thread of the drill pipe body is in the range of 11-19 mm.

6. The modified drill pipe according to claim 5, characterized in that, The outer wall of the first insulating positioning member is provided with a limiting part, and the second insulating positioning member and / or the second conductive connector are provided with a screwing structure; Alternatively, the outer wall of the second insulating positioning member may be provided with a limiting part, and the first insulating positioning member and / or the first conductive connector may be provided with a screwing structure.

7. The modified drill pipe according to claim 5 or 6, characterized in that: The first conductive connector is a conductive female connector, and the second conductive connector is a conductive male connector.

8. The modified drill pipe according to claim 7, characterized in that: The end faces of the first insulating positioning member and the first conductive connector facing the outside of the drill rod body are flush with the end face of the male drill rod head, and the second insulating positioning member and the second conductive connector are recessed into the female drill rod head.

9. The modified drill pipe according to claim 5, characterized in that: When the outer wall of the first insulating positioning member is provided with a limiting part, the inner wall of the male drill pipe is provided with a limiting groove that matches the limiting part; when the outer wall of the second insulating positioning member is provided with a limiting part, the inner wall of the female drill pipe is provided with a limiting groove that matches the limiting part.

10. The modified drill pipe according to claim 5, characterized in that: The first insulating positioning element includes an inner insulating positioning element ring, an outer insulating positioning element ring, and a connecting piece, wherein the inner insulating positioning element ring and the outer insulating positioning element ring are connected at intervals by the connecting piece; the second insulating positioning element has the same structure as the first insulating positioning element.

Images